chore: make update-checker more configurable and link other download pages

[PierreSchwang]

Overview

Closes #3074

Description

• make the update notification on join configurable, while not needing to disable the checker itself (e.g. console notification)
• enable / disable notification / check for builds and releases
• link to Modrinth, Hangar and SpigotMC (instead only to SpigotMC)
• new builds are linked directly to Jenkins (see linked issue)

Potential cons:

• linking to Jenkins for newer builds will result in lower download counts on the SpigotMC page (potentially for tracking purposes) - but i don't think that's too bad?

Generally more of a proof-of-concept tbf.

Console:

[22:19:35 WARN]: [com.fastasyncworldedit.core.util.UpdateNotification] An update for FastAsyncWorldEdit is available. You are 905 build(s) out of date.
You are running build 123, the latest version is build 1028.
Update at https://ci.athion.net/job/FastAsyncWorldEdit
[22:19:35 WARN]: [com.fastasyncworldedit.core.util.UpdateNotification] A new release for FastAsyncWorldEdit is available: 2.12.3. You are currently on 2.3.4.
Download from https://modrinth.com/plugin/fastasyncworldedit, https://hangar.papermc.io/IntellectualSites/FastAsyncWorldEdit or https://www.spigotmc.org/resources/13932

Ingame:

### Submitter Checklist
- [x] Make sure you are opening from a topic branch (**/feature/fix/docs/ branch** (right side)) and not your main branch.
- [x] Ensure that the pull request title represents the desired changelog entry.
- [x] New public fields and methods are annotated with `@since TODO`.
- [x] I read and followed the [contribution guidelines](https://github.com/IntellectualSites/.github/blob/main/CONTRIBUTING.md).

[dordsor21]

Should this be false by default?

[PierreSchwang]

I did not want to change the current behavior by default tbh. I think it's reasonable to keep notifications/checks for new Jenkins builds (especially because of bug fixes etc). In the end anyone can simply disable that themselves ig.

But I haven't spent much time thinking about it, so I'm open for input.